Amniocentesis is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, in which a small amount of amniotic fluid, which contains fetal tissues, is obtained from the amnion or amniotic sac, and the fetal DNA is examined for genetic abnormalities. This process also can be used for prenatal sex discernment.
Amniocentesis is generally performed between the 15th and 20th week of pregnancy; performing this test earlier may result in fetal injury. The term “early amniocentesis” is sometimes used to describe use of the process between weeks 11 and 13. However, it is not possible to use amniocentisis to obtain DNA or fetal cells from a fetus of less than 11 weeks of gestation. In addition, amniocentesis is invasive.
Amniotic fluid is a source of multipotent mesenchymal, hematopoietic, neural, epithelial, and endothelial stem cells. However, collecting these cells can result in complications. Artificial heart valves, working tracheas, as well as muscle, fat, bone, heart, neural and liver cells have been produced from stem cells isolated from amniotic fluid. Tissues obtained from amniotic cell lines show promise for patients suffering from congenital diseases/malformations of the heart, liver, lungs, kidneys, and cerebral tissue.
However, complications of amniocentesis include preterm labor and delivery, respiratory distress, postural deformities, fetal trauma and alloimmunisation of the mother (rhesus disease). Studies from the 1970s originally estimated the risk of amniocentesis-related miscarriage at around 1 in 200 (0.5%) although other more recent studies estimated the procedure-related pregnancy loss at 0.6-0.86%. Thus, a need remains for other methods that can be used to collect fetal stem cells and that can be used for fetal diagnosis.